The present invention relates to a multi-cylinder engine. Particularly, the present invention relates to a multi-cylinder engine having an intake manifold that comprises a plurality of induction pipes, each of which is connected to a cylinder head at one end thereof and at the other end thereof is extended to be away from the cylinder head, is then curved to extend along a side of a cylinder block, is curved further to approach the cylinder block and finally extends toward the side of the one end. In addition, the present invention also relates to a multi-cylinder engine having an electric device. Further, the present invention relates to a construction for mounting engine auxiliary parts on the multi-cylinder engine. More particularly, the present invention relates to a construction for mounting on the multi-cylinder engine an engine auxiliary part disposed in such a manner that upper and lower portions thereof confront a crankcase and an oil pan of the engine, respectively.
Generally, various types of auxiliary parts are mounted on a main body of a multi-cylinder engine. It is a common practice to dispose a starter motor, for imparting rotating force to a crankshaft so as to start the engine, at a position above a transmission or on one side of the engine.
Further, various electric devices are mounted on a main body of a multi-cylinder engine. For example, an alternator for charging a battery which supplies electric power to electric devices installed in an automotive vehicle is disposed on the side of an end of a crank pulley in the engine main body. It is a common practice to dispose an electrode terminal of the. alternator on the side or back of the alternator.
Namely, there is a case where a plurality of engine auxiliary parts, such as an oil pump for a power steering system, an alternator, an engine cooling water pump and a compressor for an air conditioner are mounted on one side of an engine-main body. With such an arrangement of engine auxiliary parts, a space over the one side of the cylinder block and the crankcase is insufficient for the arrangement, and this forces certain auxiliary parts to be disposed even on one side of the oil pan. As this occurs, while auxiliary parts disposed on the crankcase can be bolted directly to the crankcase, auxiliary parts disposed on the oil pan cannot be bolted directly to the oil pan. A bracket is therefore required in which the bracket is connected to the crankcase at one end and extends as far as the side of the oil pan at the other end thereof.
However, since the starter motor includes a certain arrangement of wiring extended from a battery and requires a relatively wide gap for installation, the amount in which the starter motor protrudes from the outer contour of the engine main body tends to be relatively large. This is a first drawback of the prior art.
In addition, conventionally the electrode terminal of alternator is provided at a position which directly faces a body frame or a radiator of an automotive vehicle. Therefore, there may be caused a risk that, in case the automotive vehicle comes into collision, the alternator is brought into contact with the deformed vehicle body to cause a short circuit. This is a second drawback of the prior art.
For example, it is common that a compressor for an air conditioner is fixed with bolts which are inserted in a direction normal to the axis of the cylinders. With this construction in which the bolts are inserted in that direction, the length of the portion of the bracket which extends to the side of the oil pan tends to be increased. To cope with this, the weight of the bracket supported in a cantilever-like fashion has to be increased in order to secure a required rigidity for the bracket. This is a third drawback of the prior art.
A first aspect of the invention was made to eliminate the first drawback in the prior art. It is a primary object thereof is to provide a multi-cylinder engine which is constructed to promote further the miniaturization thereof.
A second aspect of the invention was made to eliminate the second drawback in the prior art. It is a primary object thereof to provide a multi-cylinder engine which is improved so as to make it difficult for the electrode terminal of the electric device for the engine to be brought into contact with the vehicle body in a collision.
A third aspect of the invention was made with a view to eliminating the third drawback in the prior art. It is a primary object of the invention to provide a construction for a mounting portion for engine auxiliary parts which can secure a required rigidity with the necessity of increasing the length of the bracket being eliminated.
With a view to achieving the object, according to the first aspect of the invention, there is provided a multi-cylinder engine comprising a cylinder block, a cylinder head mounted on the cylinder block, an intake manifold comprising a plurality of the induction pipes, each of the induction pipes being connected to the cylinder head at one end thereof and, at the other end thereof, extending to be away from the cylinder head, then curved to extend along a side of a cylinder block, and curved further to approach the cylinder block, and finally extending toward the side of said one end, an auxiliary part disposed in a gap defined between said intake manifold and said cylinder block.
In particular, in the above-mentioned structure it is advantageous that the auxiliary part comprises a starter motor that includes magnet switches sunk in said gap and arranged in parallel with each other.
Furthermore, in the above-mentioned structure it is advantageous that the multi-cylinder engine further comprises an electric device for the engine, the electric device located adjacent to the intake manifold, wherein an electrode terminal of the electric device is disposed at a location which confronts an end face of said intake manifold in a direction in which the cylinders are arranged.
In addition, in the above-mentioned structure it is advantageous when said electric device for said engine comprises an alternator.
According to the construction, since the dead gap can be used effectively, useless gap can be reduced so as to promote the miniaturization of the entirety of engine.
With a view to attaining the object, according to the second aspect of the invention, there is provided a multi-cylinder engine comprising an electric device (for example, an alternator 4 in an embodiment) for the engine, a component (for example, an intake manifold 15 in the embodiment) fixed at a position adjacent to the electric device; wherein an electrode terminal of the electric device is disposed at a location which confronts an end face of the component in a direction in which cylinders of the engine are arranged.
In particular, in the above-mentioned structure it is advantageous that the electric device for said engine comprises an alternator and the component is an intake manifold.
According to the construction, even if the vehicle body is deformed in a collision, since it is protected by the intake manifold, or the like, the contact of the electrode terminal with the deformed vehicle body is made difficult.
With a view to achieving the object, according to the third aspect of the invention, there is provided a construction for mounting an engine auxiliary part (a compressor 6 for an air conditioner as described in an embodiment) on an engine, the mounting construction comprising bolts threadedly fastened from a side of an engine main body to fix the engine auxiliary parts to the engine main body at the upper and lower positions of the engine auxiliary part while the upper and lower portions of said engine auxiliary part confronts a crankcase and an oil pan, respectively, wherein axes of said bolts are inclined relative to an axial direction of a cylinder of said engine.
According to this construction, the side of the engine auxiliary part, which faces the oil pan, can be made closer to the crankcase.
Additionally, according to the third aspect of the invention, there is provided the engine auxiliary part being disposed on one side of the engine main body and apart from the engine main body, and the engine auxiliary part being driven by an endless belt for commonly driving the other auxiliary parts.
According to this construction, in trying to drive the plurality of engine auxiliary parts with a common endless belt, in order to secure a certain angle of belt wrap relative to pulleys, the auxiliary parts have to be disposed close to, and apart from, the engine main body laterally in an alternately zigzagged fashion, respectively, but when the axes of the fixing bolts of the auxiliary parts disposed apart from the engine main body are inclined the side of the auxiliary parts which faces the oil pan can be made closer to the crankcase.
Additionally, according to the third aspect of the invention, there is provided a hook-shaped temporary locking member disposed at a location where at least the upper portion of said engine auxiliary part is fixed to said engine main body.
According to this construction, the necessity of holding the auxiliary parts while the bolts are passed through can be obviated.